Apparatus for manufacturing granulated material

ABSTRACT

A mechanism for making granulated material from a viscous substance includes a vessel charged with the substance and having a discharge arrangement such as a slit through which the substance can flow onto a cooling surface. A belt disposed above the cooling surface is passed across the slit of the vessel. The belt has openings arranged to periodically come into alignment with the slit to allow the substance to flow therethrough. The belt is a thin metal belt strengthened by sleeves projecting from respective ones of the openings in a direction away from the vessel.

BACKGROUND OF THE INVENTION

The invention refers to an apparatus for manufacturing granulatedmaterial from free-flowing viscous substances that are made into dropsand solidify or gel, consisting of a vessel, charged with thefree-flowing substance, with an outflow slit which, for forming thedrops, is intermittently opened or closed by a perforated belt that isperiodically moved past them.

An apparatus of this kind is known from EP 0 134 944 B1, where anendless continuously recirculating belt is guided about two reversingpulleys, of which one at least is driven. The belt of this publicationis made from a plastic material, for example PVC, in order to give thebelt sufficient elasticity to permit its running about the pulleys andlying against the vessel. However, it is a characteristic feature ofplastic belts that they wear and age relatively rapidly. This may leadto the need to provide for relatively frequent belt changes, causingproduction stoppages, or else, after longer periods of operation, thebelt may no longer lie sufficiently close against the discharge slit ofthe vessel in which case its operation will deteriorate unless the beltis currently re-tensioned.

Now, it is the object of the invention to provide a belt that has aconsiderably longer service life and that does not offer the problems ofelastically resilient belts.

SUMMARY OF THE INVENTION

The invention proceeds from the consideration that while metal belts,especially steel belts, would of course offer the desired beltproperties, the relatively small dimensions of the reversing pulleys ofthe before-mentioned apparatuses and the flexibility necessitatedthereby, would require the belts to be made very thin so that theiropenings would not have the necessary volumes to enable the desireddrops to be formed. The invention now provides that, while the belt isconfigured as a thin metal belt, all its perforation openings areprovided with sleeves protruding from its surface opposite the vessel.This configuration makes it possible to use a sufficiently thin steelbelt that offers sufficient mechanical and aging stability while at thesame time its openings have a sufficiently large volume for forming thedrops.

According to an advantageous further development of the subject-matterof the invention, the sleeves may be provided with collars lying againstthe vessel surface of the metal belt, and the spaces between the collarsand the sleeves may be filled up with a layer flush with the collars.The layer may consist, for example, of a plastic layer which then doesnot have to absorb any tension forces.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention is depicted in the drawings with reference to exemplaryembodiments, and will be explained below. In the drawings:

FIG. 1 shows a schematic vertical sectional view of an apparatus formanufacturing granulated material; according to the invention

FIG. 2 shows a top view of the apparatus according to FIG. 1;

FIG. 3 shows an enlarged section through the perforated belt used in theapparatus according to FIGS. 1 and 2, taken along line 3--3 in FIG. 2;and

FIG. 4 shows a view of a variant of the perforated belt similar to theview of FIG. 3.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS OF THE INVENTION

FIGS. 1 and 2 show an endless continuously recirculating belt (2) abovea conveyor belt (1), especially a cooling belt designed as a steel belt,the belt (2) being guided about two reversing pulleys (3 and 4) that aremounted, in a manner not shown in detail, in a support frame (7) abovethe conveyor belt (1). The reversing pulley (3) is driven in thedirection indicated by arrow (5). FIG. 2 shows that this is achieved bythe fact that the supporting shaft (3a) of the reversing pulley (3) isprovided with a gear (6) which latter is driven by an electric motor (8)via a pinion (7). However, it would of course also be possible to use achain or belt drive, especially a V-belt drive.

The two reversing pulleys (3 and 4) are supported in such a way thattheir mutual distance can be adjusted within given limits. To this end,the reversing pulley (4) is retained in a longitudinal slot (9),indicated in broken lines in FIG. 1. The distance between the reversingpulleys (3 and 4) can be adjusted by means of a spacer consisting of thetwo parts (10a and 10b) and being provided with a screw bolt (11).Spacers of this type are provided on both sides of the reversingpulleys.

The continuously recirculating belt (2)--only a section of the lower run(2a) is shown in FIG. 3--consists of a perforated metal belt, especiallya steel belt (25) having a very small thickness--as can be seen in FIG.3. Consequently, this thin steel belt (25) can be mounted and guided onthe reversing pulleys (3 and 4) even in the presence of smalldimensions.

The perforations (12) provided in the steel belt (25), which in theillustrated embodiment are circular in shape--are each provided with aninserted sleeve (26) that has its collar (26a) in contact with, and forexample connected by welding to, a surface of the steel belt (25) whichfaces a tabular body (14) during circulation of the steel belt (2). Thefree spaces remaining between the collars (26a) of the sleeves (26) arefilled up with a layer (27), especially a layer of a plastic material,so that the inner surface of the belt (2) exhibits a smooth surface.

As can be seen in FIG. 1, the steel belt (2) is in contact with thecurved outer surface of the tubular body (14) that is provided, on itsouter surface facing the lower run (2a) of the belt, with a slit (15)that extends transversely to the belt (2) and that is either closed bythe perforated belt (2) lying closely against it, or released every timeit is passed by a row of openings (12).

The tubular body (14) comprises a guide channel (19) for a viscous andfree-flowing compound that is supplied in free-flowing, especiallyheated, condition in the direction indicated by arrow (17). Openingsextending from this guide channel (19) open into the slit (15) that isconfigured as an open groove. If, therefore, the supply channel (19) ischarged with the material to be formed into drops, the latter may dropinto the slit (15) and from there through the sleeves (26) and onto theconveyer belt formed by the cooling belt (1). This is possible in spiteof the relative thinness of the steel strip or belt (25) because thesleeves (26) provide volumes sufficient to accommodate a given quantityof the--in the present example hot--compound arriving from the tubularbody (14) and to dispense it in drop form onto the surface of thecooling belt (1) where the compound solidifies in the form of smalllentil-shaped bodies.

In order to maintain the temperature of the compound to be formed intodrops stable throughout the apparatus, the tubular body (14) is heatedin a manner not shown in detail. In addition, the whole apparatus isclosed by a cover hood (22). Directing devices (14b) in the form ofradially projecting ribs serve to urge the product, that emerges fromthe tubular body, back upon the inner belt surface with its openings(12).

FIG. 4 shows a variant of the perforated belt (200) which is providedwith inserted sleeves (26') in the same manner as in the embodimentshown first, whereas the sleeves are designed in this case as nozzlesmade from an elastically deformable material. The sleeves (26') comprisean insertion bevel (30) on one end, and an all-around locking groove(31) provided in the area of its other end, that serve for positivelyretaining the steel belt (25) of the belt (200). The material of thesleeves (26') being elastic, as for example a plastic material, theinsertion bevels (30) of the sleeves (26') can be pressed into theopenings of the steel belt (25) so that their locking grooves (31) getlocked in the openings. Just as in the case of the before-mentionedembodiment, the layer (27) provides again a smooth contact surface onthe side of the collar (26'a).

I claim:
 1. Apparatus for manufacturing granulated material from afree-flowing viscous substance that is made into drops which solidify orgel, comprising:a vessel charged with the free-flowing substance andhaving a discharge opening arrangement; a pair of rotatable pulleysdisposed on opposite side of the vessel; a belt perforated withopenings, the belt extending around the pulleys, a portion of the beltdisposed between the pulleys being arranged to move across the dischargeopening arrangement so that to move the openings of the beltperiodically come into alignment therewith to open the discharge openingarrangement and permit the free-flowing substance to flow therethrough,the belt comprising a thin metal strip having said openings formedtherethrough, and sleeves protruding from respective ones of theopenings in a direction away from the vessel.
 2. The apparatus accordingto claim 1, wherein each sleeve is provided with a collar lying againsta surface of the strip which faces the vessel, spaces on that surfacedisposed between the collars being filled with a layer of material, thelayer being flush with the collars.
 3. The apparatus according to claim2, wherein the material of the layer is plastic.
 4. The apparatusaccording to claim 1, wherein the sleeves are positively held on thestrip.
 5. The apparatus according to claim 4, wherein the sleeves arewelded to the strip.
 6. The apparatus according to claim 4, wherein thesleeves are formed of plastic.
 7. The apparatus according to claim 6,wherein each of the sleeves includes a locking groove locked in arespective opening.
 8. The apparatus according to claim 7, wherein anend of each sleeve disposed opposite the collar is beveled.
 9. Aperforated belt for use in the manufacture of granulated material from afree-flowing viscous substance, the belt comprising a metal strip havingopenings extending therethrough and sleeves protruding from respectiveones of the openings.
 10. The perforated belt according to claim 9,wherein each sleeve is provided with a collar lying against a first sideof the strip, spaces on that side disposed between the collars beingfilled with a layer of material which lies flush with the collars, thesleeves projecting from a second side of the strip.
 11. The perforatedbelt according to claim 10, wherein the material is plastic.